Abu Dharr would hear a hadith from the Messenger of Allah ﷺ containing some strict ruling, then he would set out to his people in peace. Afterwards, the Messenger of Allah ﷺ would grant a concession regarding that ruling, but Abu Dharr would not hear of it, so he would hold fast to the strict version.
كان أبو ذر يسمع الحديث من رسول الله ﷺ فيه الشدة، ثم يخرج إلى قومه يسلم عليهم، ثم إن رسول الله ﷺ يرخص فيه بعد فلم يسمعه أبو ذر، فيتعلق أبو ذر بالأمر الشديد.
Ahmad (17137) narrated it from Hasan Ashyab, who said, Ibn Lahia narrated to us, Ubaydullah bin Mughira narrated to us, from Yaala bin Shaddad bin Aws, who said, Shaddad bin Aws said, and then he related it. Its chain is hasan, containing Ibn Lahia, and the one narrating from him, Hasan Ashyab, is Hasan bin Musa Ashyab, one of the trustworthy narrators, though he narrated from Ibn Lahia after his mixing up occurred. However, he has been corroborated, for Tabarani (7166) narrated it via Ibn Wahb, from Ibn Lahia, with the same account. Abdullah bin Wahb is one of the Abadila whose narrations from Ibn Lahia are accepted.I say, in this there is an excuse offered for Abu Dharr, that what is reported about him regarding harshness in certain matters was due to this very reason, and Allah knows best. This is why the scholars warned that anyone who undertakes the pursuit of knowledge must be knowledgeable about the abrogating and the abrogated.Abu Abdul-Rahman Sulami, the companion of Ali bin Abu Talib, said, Ali came upon a judge who was passing judgment and said to him, "Do you know the abrogating from the abrogated?" He said, "No." Ali said, "You have destroyed yourself and destroyed others."Bayhaqi narrated it in al-Madkhal (184) via Shuba, from Abu Husayn, who said, I heard Abu Abdul-Rahman, and then he related it. Abu Khaythama also narrated it in al-Ilm (p. 120) via Sufyan, from Abu Husayn, with his chain, similarly. Something similar has also come from Ibn Abbas. See al-Madkhal (185).